US 2013/0075306 A1Published application

Multi-stage counter-current froth settler and method of use

AssigneeTotal E&P Canada Ltd.

InventorsAli MILANI, Alan RHODES

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Abstract

A method for recovery of bitumen from a bitumen-containing froth utilizes solvent and a single, froth settling vessel having a plurality of internals therein. The froth is first diluted with enough solvent to reduce the viscosity of the froth and the diluted froth is added to the vessel above the internals. Additional of the solvent is added to the vessel, either below the internals, intermediate the internals or both and is flowed counter-current to the diluted froth which is flowing downwardly over the plurality of internals. A gradient of solvent concentration relative to hydrocarbon concentration is formed through the internals which act as multiple stages of separation. The product, being bitumen and other light components, are carried with the solvent to the top of the vessel. The heavier components such as water, solids and asphaltene aggregates fall to the bottom of the vessel by gravity. Where paraffinic solvents are used, the solvent to bitumen ratio for the initial dilution of the froth is kept below a ratio at which the asphaltenes are rejected. Substantially all of the asphaltene rejection occurs in the settling vessel as the solvent to bitumen ratio increases therein.

Claims22

Dependent claims

A method for separation of at least bitumen, solids and water from a bitumen froth in a single vessel, the method comprising:

diluting the bitumen froth with a solvent for reducing the viscosity thereof;
feeding the diluted bitumen froth to a vessel, the vessel having a plurality of spaced apart internals positioned between a feed inlet, adjacent a top of the vessel for receiving the diluted bitumen froth, and a reject outlet at a bottom of the vessel, the plurality of spaced apart internals forming a plurality of stages therebetween, the diluted bitumen froth flowing downward through the plurality of internals;
and
introducing additional of the solvent to the vessel through one or more solvent inlets positioned below the internals, the additional solvent flowing upwardly therein, counter-current to the diluted bitumen froth, through the plurality of stages of internals and forming a gradient of solvent concentration relative to hydrocarbon concentration therein, a highest concentration of solvent being at the bottom of the vessel and a lowest concentration of solvent being at the top of the vessel, wherein
the at least solids and water settle through the plurality of stages of internals by gravity to the bottom of the vessel for removal therefrom;
and
at least the bitumen is dissolved in the solvent for forming a product, the product rising through the plurality of stages of internals through buoyancy to a product outlet adjacent the top of the vessel for removal therefrom.

4 more elements

Dependencies are inferred from the claim text.